The majority of men with suspected prostate cancer undergo 12-core biopsy sampling guided by transrectal ultrasonography (TRUS); however, this procedure often leads to false-negative diagnoses and can result in undertreatment and/or the need for further clinical monitoring. Now, prospective data from a large cohort of men requiring diagnostic investigations for suspected prostate cancer demonstrate the potential of MRI-targeted prostate biopsy, either alone or in combination with TRUS-guided sampling, to overcome these limitations.

A total of 2,180 men with an elevated serum prostate-specific antigen level or an abnormal digital rectal examination (DRE), with MRI-visible lesions, underwent combined biopsy sampling, involving both TRUS-guided and MRI-guided approaches. Among the 2,103 patients whose data were eligible for analysis, 408 underwent radical prostatectomy.

Credit: Reproduced from Stabile, A. et al. Nat. Rev. Urol. 17, 41–61 (2020), Springer Nature Limited.

Both methods resulted in a diagnosis of prostate cancer in approximately half of all men (52.5% with TRUS-guided sampling and 51.5% with MRI-guided sampling). However, MRI-guided procedures resulted in significantly fewer diagnoses of low-grade disease (Gleason grade group 1; P = 0.01) and significantly more diagnoses of high-grade disease (Gleason grade groups 3, 4 and 5; P = 0.004, P < 0.001 and P = 0.003, respectively) than the TRUS-guided approach.

Addition of data from MRI-guided sampling to that obtained with TRUS resulted in a diagnosis of prostate cancer in an additional 208 men (9.9%), of whom 59 were diagnosed with clinically significant disease (defined as Gleason grade group ≥3). This combination also resulted in 74 new diagnoses of clinically insignificant prostate cancer (Gleason grade group 1) and 134 men with grade group 1 disease being reclassified as having grade group ≥2 disease.

A total of 404 men subsequently underwent radical prostatectomy, of whom 58 (14.4%) had their grade group upgraded on examination of the surgical specimen, including upgrading to clinically significant disease in 3.5%. When classified using only a single diagnostic procedure, 41.6% and 16.8% of patients with prostate cancer diagnosed using only TRUS-guided biopsy required upgrading and upgrading to clinically significant disease, respectively, compared with 30.9% and 8.7% for MRI-targeted sampling (P ≤ 0.002 for all comparisons). Fewer than 4% of patients diagnosed using any modality required downstaging following radical prostatectomy.

When only one diagnostic procedure is possible, MRI-targeted biopsy seems to be superior to the TRUS-guided approach

These findings support the use of combined biopsy sampling, which provides the lowest level of diagnostic uncertainty. When only one diagnostic procedure is possible, MRI-targeted biopsy seems to be superior to the TRUS-guided approach. Nonetheless, a subset of clinically significant cancers will continue to go undetected using MRI-targeted biopsy alone.

This article is modified from the original in Nat. Rev. Clin. Oncol. (https://doi.org/10.1038/s41571-020-0358-2).